Keira Knightley felt like she was back in physics class

Keira Knightley felt like she was back in physics class when learning about code for ‘The Imitation Game’.

The 29-year-old actress stars as wartime codebreaker Joan Clarke in the drama and admits she and her co-stars were left baffled during preparatory sessions with experts who tried to explain how the systems used worked.

She said: “These people were geniuses! I think you’d at least need some form of higher mathematics to understand. Did I take any of it in? No.

Can I explain any of it? No. They tried to teach us, they brought in enigma machines and tried to bring in this very lovely man who was desperately trying to explain to us how it worked and how the machine Alan [Turing] made would work but it just went straight over… there was nothing.

“I went immediately [that I didn’t understand], I felt like I did when I was 14 and in physics class and didn’t understand a word, so I had to admit straight away, it took me straight back.”